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If you’ve seen the term CSO (Combined-Sewer Overflows) go by here in the past three-plus years, it was likely in connection with the King County projects meant to reduce overflows at the county-run Murray (Lowman Beach) and Barton (Fauntleroy ferry dock) Pump Stations. However – the city of Seattle is under orders (as part of this agreement with the feds) to cut down on overflows from some of their pump stations too, and that includes two spots in West Seattle where overflows go into Longfellow Creek (see the map above). As was the case for the county, possible solutions might include “roadside raingardens” – the city’s term – in planting strips, or extra storage.

Nope. Combined-sewer overflow refers to what happens when a pump station is overtaxed during a fairly heavy rainstorm and has to go into overflow mode, with the “combined sewer” (both stormwater and sewage) output heading into the water body instead of to a treatment plant. If you are noticing a sewer-y smell down there, definitely contact the King County Wastewater Treatment Division in case it’s one of their facilities – there is of course the stormwater plant there south of Alki Point …

A County rep told me (at River Fest) that humongous cisterns could be purchased with a nearly 90-95% rebate – super good deal for folks. Wish they’d move the eastern boundary further east though. I wanna harvest some rain for free too.

What I didn’t mention first – it’s alluded to on the map, though – is the Rainwise program, for which a much bigger area will be eligible – it involves raingardens on your own property. I toured some north-end raingarden/RainWise zones with SPU reps last week and will include some of that background in a longer story.

Does anyone have any details on water quality in the Alki/Lincoln park areas? I swim out in the sound on a regular basis and am trying to see where it’s safest to swim.

I am also interested in learning if there is a corrolation between the tides (max high/lows) and water quality in general. The greater the tide max/min, the more the overall water (combined fresh and salt) mixes diluting the fresh water that is introduced into the sound. That is in my theory. (Given: the fresh water is lighter than salt water is stays on the top layer, and even if the outflow of CSO is colder than the water in the sound it would still stay on the top layer and would be slow to mix)